My knee-jerk reaction is to say there are a lot of nasty, spiteful, jealous, cruel people posting here.
When Opie says she's paying off her daughter's car finance, you understand that she's using her own money to that, right?
As in she hasn't cloned your bank card, and isn't taking your money to pay for it. She's not "taken" anything at all from you or affected your finances in any possible manner.
She's not "stolen" the money for those car payments from your parent/s or caregiver's. She's not the reason mummy and daddy didn't buy you a shiny new car.
And maybe, just maybe, she's helping her daughter out because she wants to. Maybe she's in a comfortable and secure enough position that she can help her daughter out without becoming financially destitute herself?
Whatever the case may be, she's not causing you any harm... so maybe grow up a bit and stop attacking her as if she was enacting some personal vendetta against you?